Here we’ll focus on the risk factors, symptoms of Long COVID and will examine some of the possible causes.
Risk factors are very hard to pin down, although there are some correlative evidence of who are more at risk of Long COVID.
Illness Severity: Severity of illness does not exclude the possibility of experiencing long COVID. Even people who have had mild infections are not protected. However, there tends to be a relationship between severity of illness and prevalence of Long COVID. Various biomarkers may point to more consistent evidence of increased Long COVID risk as higher levels of pro-inflammatory biomarkers and immune cells may indicate an increased risk of Long COVID occurring.
Age also contributes to prevalence of Long COVID, as elderly patients are more likely to experience symptoms of Long COVID, although compounding variables such as overall poorer health and increased risk of severe illness are likely to play roles in Long COVID’s prevalence among this demographic.
Sex: Some researchers have suggested that women are more likely to experience Long COVID, although that appears to be more related to persistent changes in cognition such as brain fog, depression and chronic fatigue specifically. In that sense, a better rationale would be to suggest that the presentation of post-COVID sequelae may be sex-dependent and considerations should be taken to understand the prevalence of certain symptoms between the sexes. Why sex differences are likely to contribute to post-COVID sequelae is still up for debate, although hormonal and other physiological differences may help to explain these sex differences.
Comorbidities are an important factor when assessing post-COVID sequelae. People with higher levels of comorbidities are likely to experience higher rates of Long COVID, likely indicating a possible exacerbation of chronic symptoms.
Overall, nearly anyone can experience Long COVID. The question remains which demographics may experience greater and more severe symptoms, which is yet to be fully determined.
Symptoms of Long COVID
In some respects, the number of post-COVID sequelae can rival that of COVID itself. The scope of symptoms spans neurological issues such as brain fog and persistent headaches to cardiac issues like arrhythmia, and even some more strange symptoms such as hair loss and impotence in some men. This really encapsulate the broad nature of COVID and its ability to operate as a respiratory infection, cause vascular disease, and its possible roles in neuroinvasion. What’s interesting is that symptoms may not just be persistent, but may also be recurring in an on-again/off-again fashion.
Here are a few broad representations of some of these symptoms. Note that these are a non-exhaustive list of symptoms:
In general, symptoms of Long COVID include fatigue, persistent coughs and continued loss of smell and taste (taken from Garg et. al.):
These are non-specific but often experienced persistent symptoms of COVID-19, even by patients with a milder form of the disease. Persistence of some of the acute illness physical symptoms, including dyspnea, fatigue, post-exertional malaise, chest pain, and cough, are the most common manifestation of the Long-COVID-19.12,14–19 An online-questionnaire-based study on 2113 post-COVID-19 patients reported only 0.7% of symptom-free subjects at 79 days after acute COVID-19 pneumonia.14 It also reported fatigue (87%) and dyspnea (71%) as the most prevalent symptoms at 79 days after onset of acute illness.14 A survey-based study consisting of post-discharged hospitalized subjects (n=143) found fatigue (53%), dyspnea (43%), loss of memory (34%), sleep disorders (30.8%), impairment of concentration (28%), and joint pain (27%) as the frequently reported persistent symptoms at 110 days after discharge from the hospital.15
Because the scope of symptoms are so broad it may be more pertinent to define some of the symptoms and describe some of their causes further on. This list is not exhaustive and you are likely to come across plenty of other symptoms in the literature or within various online communities.
Ageusia: Loss of Taste
Anosmia: Loss of Smell
Brain Fog: a nonmedical term that refers to an inability to think clearly
Dysautonomia: Dysautonomia refers to the dysfunction of the autonomic nervous system. It mainly refers to the failure of both the sympathetic and parasympathetic nervous system to function properly, although an overactive ANS also is included under dysautonomia. Usually changes in autonomic functions such as blood pressure, digestion, and heart rate are an indication of dysautonomia.
Dyspnea: Shortness of breath
Encephalopathy: Disorders and diseases of the brain (this is likely referring to broad neurological dysfunctions seen in Long COVID)
Erythematous Rash: a rash that presents with typical redness on various parts of the body
Malaise: A general feeling of uneasiness, weakness, or discomfort usually associated with an illness
Myalgia: Muscle pain
Myocarditis: Inflammation of the myocardium (the tissues of the lower chambers of the heart) which may lead to impaired heart beats and arrhythmia
Pericarditis: Inflammation of the pericardium (the fibrous sac that surrounds the heart) which usually leads to impaired heart function due to constriction of the heart.
Urticarial Rash: raised, bumpy rashes akin to hives
A listing of symptoms runs a little hollow without the perspectives of those suffering from Long COVID to provide their own accounts. Testimonials usually help to put a face to the disease and provides a more empathetic view into how people would describe their symptoms.
A qualitative study by Ladds et. al. provides some first-hand accounts of people’s perceptions of their Long-COVID and how it altered their daily lives. It’s an interesting collection of people’s own symptoms and struggles with maneuvering within the medical system and getting their symptoms acknowledged, including some of the stigma they have experienced from friends and family (not included here, but check out the paper for those anecdotes):
Many participants described themselves as previously fit and active. They described having to come to terms with a dramatic decline in their ability to perform basic everyday activities.
And the fatigue is literally like hitting a wall. I can’t stay awake any more. It’s just like, wow, I have to go to bed.
(Individual interview, Adam).
Participants had discovered the need to establish new routines and explicit self-disciplinary measures. These included counting steps and planning out visits to the shops to avoid inevitable exhaustion if they over-exerted themselves:
My energy levels returning, that took me weeks and weeks. I mean … this morning I went for a two hour walk and actually when I got back, I slept for two and a half hours.
(Individual interview, Siobhan)
Symptoms such as fatigue and cognitive blunting (“brain fog”) severely limited the prospect of returning to work or finding new employment, as this office worker describes:
I'm not working, I haven't... I wasn’t able to go back to work and then I got made redundant. I'm... I can't even imagine how I'm going to find a new job yet. In the last week, I'm wondering because my brain fog seems to have lifted and it's feeling possible finally, after nearly six months, that I might one day find a new job. But my life is just nothing like it was and it's not really the life I want, you know; I need to improve.
(Individual interview, Anil)
A few participants in our sample (both clinicians and non-clinicians) made comparisons with post viral fatigue states like myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS). They expressed empathy and newfound solidarity with people suffering with these conditions. More commonly, our respondents felt the fatigue they were experiencing was distinct, and a consequence of their organ damage.
It’s interesting that the patients drew parallels to ME and CFS. As indicated in my prior post, CFS has been blown off as being attributed to mass hysteria, likely because women are more likely to present with CFS. Even now CFS tends not to be taken seriously by many medical professionals. This would at least suggest that there may be a relationship between post-viral syndrome and CFS as a whole.
With such a broad list of symptoms it’s easy to see why attributing many of these symptoms to Long COVID may prove difficult. Nonetheless, its existence and wide array of symptoms speaks more of the pervasive nature of COVID and how it affects many organs and tissues. It’s quite understandable why it may be difficult to diagnose. However, the realities of Long COVID should be acknowledged in order to find proper ways to treat the disease.
This post was broken up and the section on causative factors will be released as the next installment. Apologies for the constant emails when this occurs. Please let me know if this creates problems with constant spamming.
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